Skid-steer loader

A skid loader or skid-steer loader is a small rigid frame, engine-powered machine with lift arms used to attach a wide variety of labor-saving tools or attachments. Though sometimes they are equipped with tracks, skid-steer loaders are typically four-wheel vehicles with the wheels mechanically locked in synchronization on each side, and the left-side drive wheels can be driven independently of the right-side drive wheels.
The wheels typically have no separate steering mechanism and hold a fixed straight alignment on the body of the machine. By turning the left and right wheel pairs at different speeds, the machine turns by skidding, or dragging its fixed-orientation wheels across the ground. The extremely rigid frame and strong wheel bearings prevent the torsional forces caused by this dragging motion from damaging the machine.
The skid-steering vehicle is turned by generating differential velocity at the opposite sides of the vehicle. Like tracked vehicles, the high ground friction produced by skid steers can rip up soft or fragile road surfaces. They can be converted to low ground friction by using specially designed wheels such as the Mecanum wheel.
Skid-steer loaders are capable of zero-radius, "pirouette" turning, which makes them extremely maneuverable and valuable for applications that require a compact, agile loader.
Unlike in a conventional front loader, the lift arms in these machines are alongside the driver with the pivot points behind the driver's shoulders. Because of the operator's proximity to moving booms, early skid loaders were not as safe as conventional front loaders, particularly during entry and exit of the operator. Modern skid loaders have fully enclosed cabs and ther features to protect the operator. Like other front loaders, it can push material from one location to another, carry material in its bucket or load material into a truck or trailer.
The first three-wheeled, front-end loader was invented by brothers Cyril and Louis Keller (manufacturer) in Rothsay, Minnesota, in 1957. The Kellers built the loader to help a farmer mechanize the process of cleaning turkey manure from his barn. The light and compact machine, with its rear caster wheel, was able to turn around within its own length, while performing the same tasks as a conventional front-end loader.[1]
The Melroe brothers, of Melroe Manufacturing Company in Gwinner, N.D., purchased the rights to the Keller loader in 1958 and hired the Kellers to continue refining their invention. As a result of this partnership, the M-200 Melroe self-propelled loader was introduced at the end of 1958. It featured two independent front-drive wheels and a rear caster wheel, a 12.9-hp engine and a 750-lb. lift capacity. Two years later they replaced the caster wheel with a rear axle and introduced the M-400, the first four-wheel, true skid-steer loader.[1] It quickly became the Melroe Bobcat. The term "Bobcat" is sometimes used as a generic term for skid-steer loaders. The M-440 was powered by a 15.5-hp engine and had an 1100-lb. rated operating capacity. Skid-steer development continued into the mid-1960s with the M600 loader.
Many manufacturers have their own versions of the skidloader (often referred to as a Skidsteer in the Construction Industry), including: Wacker Neuson, LiuGong, Volvo, John Deere, Case, JLG, JCB, New Holland, Gehl Company, Mustang, ASV, Caterpillar, Bobcat, Komatsu, Hyundai, and more.